As optical fibers come to be used in increasingly harsh environments, such as in jet engines, for example, the fiber connectors, and ferrules to which the optical fibers are fastened must be ruggedized to survive the much more rigorous temperature and vibration environments to which they are exposed.
An optical fiber connector, or ferrule, which is resistant to high temperature, temperature shock, and vibration may be realized in a structure in which metal coated fibers passing through the ferrule or connector are bonded to the ferrule or connector through a metallic compact which is prepared in situ in the interior of the ferrule or connector.
The term "bonding" is used in its broadest sense to including sintering and brazing of powdered metals or brazing fillers. "Brazing" as used herein means a method of joining metals by applying heat to a brazing filler which has a melting temperature below that of the metals being joined. As the brazing filler melts, there is a flow of the brazing filler by capillary action to wet the metals to be joined and create a metallurigical bond between them at the molecular level. "Sintering" as used herein means a welding together of metallic particles in a powder form at a temperature below the melting point of the metallic particles but above one-half (1/2)of the melting point. While "sintering" may occur solely with the application of heat, it may also take place in so-called hot pressing or sintering under pressure by the simultaneous application of temperature and pressure.
The invention comprises a two part ferrule or connector structure in which each part has a conical shaped interior cavity. When assembled the ferrule has an interior chamber in form of a conical annulus surrounding the metal coated optical fibers passing through the connector. The chamber is filled with a metal powder or brazing filler. The connector is subjected to temperature and pressure to form a metal compact by sintering or brazing. The materials in the chamber are bonded to the optical fiber bundle and to the interior wall of the connector chamber. This bonding of the optical fiber bundle, and the wall of the connector results in a connector with excellent temperature and vibration resistance characteristics.
It is therefore a principal objective of the invention to provide a method and apparatus for bonding optical fibers to a connector.
It is a further objective of the invention to produce an optical fiber connector which is operative at high temperatures and high vibration levels.
Yet another objective of the invention is to provide an optical fiber connector in which the optical fiber is physically bonded to the connector element.
Still another objective of the invention is to provide a high temperature connector for optical fibers in which the optical fibers are physically bonded to the connector by sintering.
Yet a further objective of the invention is to provide a method for producing a high temperature optical fiber connector through a sintering of a powdered compact.
Other objectives and advantages of the invention will become readily apparent as the description proceeds.